Abstract
BACKGROUND: Type 2 diabetes mellitus (T2DM) is often accompanied by vitamin D (VitD) deficiency, chronic inflammation, and altered bone metabolism, yet, the interplay between these comorbidities and T2DM has not been adequately determined. OBJECTIVE: This study aimed to determine the associations between serum VitD levels, bone turnover markers, and inflammatory cytokines in Emirati patients with T2DM, and their interaction in relation to glycemic control. In addition, to compare the above parameters between the well-controlled and poorly controlled glycemic groups. MATERIALS AND METHODS: In this cross-sectional study, 128 Emirati adults aged 25-65 years with T2DM were recruited. Serum levels of VitD, osteocalcin, bone resorption marker β-cross-linked telopeptide (β-CTX), inflammatory markers (IL-6, TNF-α, CRP), and glycosylated hemoglobin (HbA1c) were measured. Non-parametric tests (Spearman correlation, Mann-Whitney U) and multivariate logistic regression were used for analysis. RESULTS: Patients with poorly controlled glycemia exhibited significantly elevated IL-6, TNF-α, and CRP levels compared to that in the well-controlled group (P < 0.001). Osteocalcin levels were markedly lower in the poorly controlled group, while β-CTX showed insignificant differences. Serum VitD was inversely correlated with IL-6 and TNF-α. In logistic regression analyses, elevated IL-6 was independently associated with low bone mineral density (P = 0.007). CONCLUSION: An interplay exists between VitD, inflammatory markers, and bone health in Emirati patients with T2DM, where VitD was linked with bone density but not with bone markers. Poorly controlled glycemia was associated with low osteocalcin levels and elevated inflammatory markers.